Department of Health Seal

TGM for the Implementation of the Hawai'i State Contingency Plan
Section 6.0
GROUNDWATER AND SURFACE WATER SAMPLING GUIDANCE

6.0 GROUNDWATER AND SURFACE WATER SAMPLING GUIDANCE

The sampling guidelines presented in this section are intended to ensure that water samples collected as part of an environmental investigation are representative of the in-situ condition of the groundwater or surface water, and that data derived from these samples can be used for decision making purposes. This section also presents guidance for monitoring well construction, purging, and sampling, as well as an overview of sampling equipment available for the collection of groundwater or surface water samples.

This section refers to information in other TGM sections that are relevant to groundwater and surface water sampling. For instance, site investigations may sometimes feature groundwater as the sole media of concern, but groundwater sample collection is most frequently performed as part of a larger investigation that also involves subsurface soil sampling and/or soil vapor sampling. In either case, the initial site preparation and boring/drilling methods described in Section 5 are required for proper installation of monitoring wells.

Prior to sample collection efforts, a site-specific Sampling and Analysis Plan (SAP) and associated Quality Assurance Project Plan (QAPP) should be developed as described in Section 3.0. The SAP designates the types and quantities of samples or monitoring information to be collected; where, when and under what conditions they should be collected; and what variables are to be measured. The Quality Assurance/Quality Control (QA/QC) procedures ensure that sampling design and measurement errors are controlled sufficiently to meet the tolerable decision error rates specified in the Data Quality Objectives (DQO).